The head of a drug-testing laboratory in Switzerland has denied giving banned cyclist Lance Armstrong "the key" to avoiding detection for the blood-boosting agent EPO.

Martial Saugy, director of the laboratory in Lausanne, was responding to claims made by the head of the US Anti-Doping Agency (USADA) that he had met Armstrong in 2002 and showed him how to circumvent tests.

Saugy has previously admitted meeting Armstrong and his US Postal team manager Johan Bruyneel but called a news conference on Friday where he insisted he did so at the request of the International Cycling Union (UCI).

Saugy told reporters in Switzerland: "The answer to the question of whether I gave Lance Armstrong the key to circumvent EPO tests, is clearly no.

"I remain convinced that it (the meeting) was the right thing to do. It was not a mistake, nor naive as some have written.

"It would be paradoxical for the laboratory that reported the first case of EPO to give the key to circumvent tests.

"The fight against doping is our life's work."

The claims by USADA chief Travis Tygart has raised further questions about the UCI's involvement in the scandal.

Concerns have previously been expressed about a 'triangle' - with the UCI accepting a 100,000 US dollar donation from Armstrong in 2002 and around that time the UCI gave the Lausanne laboratory free use of a blood analyser worth 60-70,000 US dollars.

Tygart, the man who brought charges against Armstrong that led to him being stripped of seven Tour de France titles, told US television programme 60 Minutes that Saugy had told him over dinner he had met Armstrong and Bruyneel at the request of the UCI in 2002 to explain how the EPO test worked.

The UCI insist that the meetings were arranged as a "deterrent" to show riders they were getting tough on doping and not to show them how to beat the system.

Tygart told 60 Minutes: "He (Saugy) sat beside me and said: 'Travis, there is a sample from Lance Armstrong that indicates Lance Armstrong used EPO'. He also told us that he had been ordered by the UCI to meet Lance Armstrong and Johan Bruyneel to explain the method of detecting EPO, something that was unusual for him.

"So I asked him: 'Did you give Lance Armstrong and Johan Bruyneel the keys to beating EPO tests?' And he nodded to say yes. He explained to them, just the two of them. As far as I know, it's unprecedented.

"It's completely wrong to meet an athlete with a suspect result and explain to him how the test works."

The UCI has set up an independent commission, including Baroness Tanni Grey-Thompson among the members, to investigate USADA's findings - including any payments from Armstrong to the organisations. The findings are expected before June.

A UCI spokesman insisted it had never tried to cover up the meeting.

"The UCI organised meetings with some riders to make them aware of the steps we were taking," said the spokesman.

"We never met to tell them how to beat the system - the purpose was to say we are working in this direction, it was just an information policy and a deterrent.

"It happened with many riders and many teams, we have never denied this meeting took place in order to inform him (Armstrong) and his team. There is nothing to hide, we are trying to be very transparent."

Armstrong is due to break his silence on the doping allegations on Oprah Winfrey's TV talk show next Thursday.